open_page

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the transparency burden and does disclose the key side effects: opening a URL in the browser, starting console/network error capture, and returning title, HTTP status, and active engine. It also implies that switching engines reopens the URL, which is useful behavioral context. It does not cover persistent browser state or teardown, but sibling tools like close_browser make this less critical.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences with no filler. The first sentence front-loads the action and ordering; the second covers return values and the engine use case. Every sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a tool with no output schema and five parameters, the description covers the essential return values, side effects, and engine usage tip, and the schema documents all parameters. Minor gaps remain around repeated calls and whether previous browser state is replaced, but the description is sufficient for an agent to call the tool correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the baseline is 3. The description adds genuine extra meaning for the engine parameter by framing it as a way to compare rendering across engines, and it connects the tool's overall purpose to capturing console/network errors. This goes slightly beyond the schema's parameter descriptions.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb and resource ('Open a URL in the browser') and clearly adds a distinct capability ('start capturing console + network errors') that separates it from sibling tools like screenshot or read_console. The instruction 'Call this first' also identifies it as the entry-point navigation tool.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly says 'Call this first,' which tells the agent when to use it relative to other tools. It also gives conditional context for the engine parameter ('re-open the same URL in a different browser engine and compare rendering'). It does not explicitly name alternatives or exclusions, but the ordering instruction provides clear usage guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.